Integrated Cryogenic Fluid Delivery System

ABSTRACT

An integrated cryogenic fluid delivery system includes a cryogenic liquid tank having an interior, a wall and a geometry. The interior of the cryogenic liquid tank contains a supply of cryogenic liquid. A fuel pickup line is positioned within the interior of the tank and is in fluid communication with a vaporizer so that the vaporizer receives and vaporizes cryogenic liquid from the tank. The vaporizer is positioned outside of the tank and is secured to the wall. The vaporizer also has a shape that conforms with the geometry of the tank.

CLAIM OF PRIORITY

The application claims priority to U.S. Provisional Patent ApplicationNo. 61/763,258, filed Feb. 11, 2013, the contents of which are herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to cryogenic fluid deliverysystems and, more specifically, to an integrated cryogenic fluiddelivery system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an embodiment of the integrated cryogenicfluid delivery system of the invention;

FIG. 2 is a perspective view of one embodiment of the vaporizer of thesystem of FIG. 1;

FIG. 3 is an end elevational view of a tank equipped with an embodimentof the system of FIG. 1; and

FIG. 4 is an cross section view of the front head shown with anadditional possible embodiment of the vaporizer of the system of FIG. 1.

DETAILED DESCRIPTION OF EMBODIMENTS

The embodiment of the invention described below provides an integrateddelivery system of liquefied natural gas (LNG) from a storage tank to ause device, such as a natural gas powered vehicle engine. It is to beunderstood that the invention may alternatively be used to deliver ordispense other types of cryogenic fluids.

With traditional LNG delivery systems, major components, such as thetank, vaporizer and valves may be separate sub-assemblies installed invarious locations on the vehicle. In accordance with an embodiment ofthe present invention, these components are integrated into a singlesub-assembly. By integrating all of the components into onesub-assembly, illustrated in phantom at 5 in FIG. 1, the effort forvehicle installation and the overall space claim for packaging may bereduced. Also, it may be possible to eliminate some components, such asexcess flow devices, that would traditionally appear on systemsfeaturing multiple sub-assemblies. Furthermore, heat from the vaporizermay be used to reduce ice build-up on tank plumbing components allowingsuperior performance in cold climates.

The invention is particularly suited for customers requiring easyassembly and minimal packaging space. Also, end user in cold weatherclimates may benefit.

Embodiments of the integrated tank concept for the system may includecomponents with non-traditional geometry and/or combined functions. Forexample, a vaporizer (described below) designed to conform to the shapeof the tank or multiple electrical functions combined into a singledevice allow for a reduction in packaging space. Also, a singlemechanical device may be configured to perform multiple functions, suchas shut-off and excess flow prevention.

An embodiment of the system of the present invention is illustrated inFIG. 1. A cryogenic tank 6 contains a cryogenic product, such as LNG. Asan example only, tank 6 may be cylindrical in shape. Pressure gauge 12and level gauging system 8 indicate the status of the cryogenic productin the tank. A fill receptacle 10 is provided to fill the tank and acheck valve 11 is provided to prevent back flow. More specifically,during filling, LNG enters receptacle 10, travels through the checkvalve 11 and up fill line 16 to exit into the head space of the tank 6.

Pressure relief devices, such as valves 17 and 19 are used to avoidover-pressurization of the tank 6. Vent valve 20 in conjunction withvent receptacle 14 allow the tank to be depressurized if needed forfueling or maintenance purposes.

A fuel pickup line 18 has a bottom opening in communication with theliquid in the bottom of the tank 6. In normal use of the system, thatis, during dispensing or delivery of vaporized LNG, liquid valve 22 isopen, while vent valve 20 is closed. To dispense LNG, or deliver it tothe vehicle engine or other use device, automatic delivery valve 24 isopened. Due to the pressure in the head space of the tank, when valve 24is opened, the LNG travels up line 18 and through line 26, includingthrough valve 22. The LNG then travels through vaporizer 28 whichvaporizes the LNG to a vapor phase, which then flows to the use devicethrough valve 24.

One or more safeguards are in place in case of fuel line breakage orrupture. Excess flow valve 30 may be in place to directly sense a flowof LNG though line 26 that exceeds normal operational characteristics atwhich point the valve 30 closes. Alternatively or in conjunction withthe aforementioned safeguard, low temperature switch 32 can sense thefuel temperature downstream of vaporizer 28 and may signal the closureof automatic valve 24 if necessary. This latter protection protectsagainst failures such as fuel line breakage between the tank 6 and theuse device and against failures of the vaporizer 28 itself includinginsufficient heat exchange fluid flow--both conditions resulting in coldfuel temperature downstream of the heat exchanger.

A delivery pressure regulator 34 may be used to limit pressure deliveryof the gas to the use device if the maximum allowable pressure of theuse device exceeds the pressure setting of the primary relief valve 17.The delivery pressure regulator 34 may be positioned either within oroutside of the cylindrical shroud (62 of FIG. 3).

Depending upon the system pressure, vapor may be withdrawn from tank 6through economizer regulator 36 which is connected to fuel pickup line18 through line 38 and communicates with the head space of the tankthrough lines 40 and 42. When the vapor pressure in the tank head spaceexceeds a predetermined level, economizer regulator 36 opens so thatvapor from the head space travels through lines 42, 40 and 38 to lines18 and 26, and ultimately out of the tank through regulator 34.

While, as indicated above, manual valve 20 is typically closed, it maybe opened during filling to reduce pressure or vent gas back to thefueling station. Manual valve 22 may be shut for maintenance purposes.

An embodiment of the vaporizer 28 of FIG. 1 is indicated as aperspective view in FIG. 2. As illustrated in FIGS. 2 and 3, thevaporizer is provided with a conformal geometry. This device may be ashell and tube style heat exchanger utilizing warm engine coolant tovaporizer cold LNG. More specifically, the LNG from line 26 enters port44 of the vaporizer and exits port 46 as vapor after traveling throughan internal tube 48 (illustrated in FIG. 3) that connects ports 44 and46. Warm engine coolant travels into the vaporizer 28 through port 50and exits through port 52 after traveling through an internal tube 54(illustrated in phantom in FIG. 3) that connects ports 50 and 52. Onepossible external geometry for the shell 56 of the vaporizer issemi-circular to conform with a cylindrical tank, as illustrated in FIG.3. One possible geometry for the internal tubes 48 and 54 of thevaporizer includes a circular helix, again as illustrated in FIG. 3.

The components of FIGS. 1 and 2 installed on a tank, along withadditional components, are illustrated in FIG. 3. As illustrated in FIG.3, the components are efficiently organized and integrated into a singlesub-assembly that fits within a cylindrical shroud 62 attached to an endwall or head of the tank to provide a compact package that takes upminimal space in an installation. The shroud, which projects from theend of the tank, as illustrated in FIG. 4, protects the components. Morespecifically, the shroud 62 creates a protected region for crashresistance.

An additional embodiment of vaporizer 28 (of FIG. 1) is indicated ingeneral at 68 in FIG. 4. In this cross-sectional view, the embodiment ofvaporizer is integral to front head 72 of tank 6. The tubes 74 whichcarry and vaporize LNG are wound around the longitudinal axis of support76 of tank 6. A second head 78 fits over the tubes and forms a space 82in which the heat exchange fluid may travel. Plumbing components shownin FIG. 3 are mounted in a similar fashion to the head of the tank andare likewise protected by shroud 62.

While the preferred embodiments of the invention have been shown anddescribed, it will be apparent to those skilled in the art that changesand modifications may be made therein without departing from the spiritof the invention, the scope of which is defined by the following claims.

What is claimed is:
 1. An integrated cryogenic fluid delivery systemcomprising: a) a tank having an interior, a wall and a geometry; b) afuel pickup line positioned within the interior of the tank; c) avaporizer in fluid communication with the fuel pickup line; d) saidvaporizer positioned outside of the tank secured to the wall and havinga shape that conforms with the geometry of the tank.
 2. The cryogenicfluid delivery system of claim 1 further comprising a shroud attached tothe wall of the tank and generally surrounding the vaporizer so as toprovide a protected region for crash resistance.
 3. The cryogenic fluiddelivery system of claim 1 wherein the vaporizer is a shell and tubeheat exchanger having a shell that conforms with the geometry of thetank.
 4. The cryogenic fluid delivery system of claim 3 wherein the tankis cylindrical and the shell is semi-circular.
 5. The cryogenic fluiddelivery system of claim 4 wherein the vaporizer includes a cryogenicfluid internal tube and a warming fluid internal tube and wherein thecryogenic fluid and warming fluid internal tubes feature circular helixgeometries.
 6. The cryogenic fluid delivery system of claim 3 whereinthe vaporizer includes a cryogenic fluid internal tube and a warmingfluid internal tube and wherein the cryogenic fluid and warming fluidinternal tubes feature circular helix geometries.
 7. The cryogenic fluiddelivery system of claim 1 wherein the wall of the tank is a first headand wherein the vaporizer includes a second head attached to the firsthead of the tank so that a warming fluid space is defined between thefirst and second heads and a cryogenic fluid internal tube is positionedwithin the warming fluid space and in fluid communication with the fuelpickup line.
 8. The cryogenic fluid delivery system of claim 1 furthercomprising: e) a delivery valve in fluid communication with thevaporizer; f) a pressure relief valve in fluid communication with theinterior of the tank; g) a regulator in communication with the fuelpickup line; i) a shroud attached to the wall of the tank and generallysurrounding the delivery valve, pressure relief valve and regulator; andj) said shroud also generally surrounding the vaporizer so that thevaporizer is adapted to provide heat to reduce ice build-up on thedelivery valve, pressure relief valve and regulator.
 9. The cryogenicfluid delivery system of claim 8 wherein the regulator is an economizerregulator and further comprising a delivery pressure regulatorpositioned within said shroud.
 10. An integrated cryogenic fluiddelivery system comprising: a) a tank having an interior containing asupply of cryogenic liquid, a wall and a geometry; b) a fuel pickup linepositioned within the cryogenic liquid; c) a vaporizer in fluidcommunication with the fuel pickup line so that cryogenic liquid fromthe tank is vaporized in the vaporizer; d) said vaporizer positionedoutside of the tank secured to the wall and having a shape that conformswith the geometry of the tank.
 11. The cryogenic fluid delivery systemof claim 10 further comprising a shroud attached to the wall of the tankand generally surrounding the vaporizer.
 12. The cryogenic fluiddelivery system of claim 10 wherein the vaporizer is a shell and tubeheat exchanger having a shell that conforms with the geometry of thetank.
 13. The cryogenic fluid delivery system of claim 12 wherein thetank is cylindrical and the shell is semi-circular.
 14. The cryogenicfluid delivery system of claim 13 wherein the vaporizer includes acryogenic fluid internal tube and a warming fluid internal tube andwherein the cryogenic fluid and warming fluid internal tubes featurecircular helix geometries.
 15. The cryogenic fluid delivery system ofclaim 12 wherein the vaporizer includes a cryogenic fluid internal tubeand a warming fluid internal tube and wherein the cryogenic fluid andwarming fluid internal tubes feature circular helix geometries.
 16. Thecryogenic fluid delivery system of claim 10 wherein the wall of the tankis a first head and wherein the vaporizer includes a second headattached to the first head of the tank so that a warming fluid space isdefined between the first and second heads and a cryogenic fluidinternal tube is positioned within the warming fluid space and in fluidcommunication with the fuel pickup line.
 17. The cryogenic fluiddelivery system of claim 10 further comprising: e) a delivery valve influid communication with the vaporizer; f) a pressure relief valve influid communication with the interior of the tank; g) a regulator incommunication with the fuel pickup line; i) a shroud attached to thewall of the tank and generally surrounding the delivery valve, pressurerelief valve and regulator; and j) said shroud also generallysurrounding the vaporizer so that the vaporizer is adapted to provideheat to reduce ice build-up on the delivery valve, pressure relief valveand regulator.
 18. The cryogenic fluid delivery system of claim 17wherein the regulator is an economizer regulator and further comprisinga delivery pressure regulator.
 19. A vaporizer for a cryogenic tankhaving a geometry comprising: a) a shell having an interior and a shapethat conforms to the geometry of the cryogenic tank; b) a cryogenicfluid inlet port and a cryogenic fluid outlet port formed in the shell;c) a cryogenic fluid internal tube positioned within the interior of theshell and connected between the cryogenic fluid inlet port and thecryogenic fluid outlet port; d) a warming fluid inlet port and a warmingfluid outlet port formed in the shell; and e) a warming fluid internaltube positioned within the interior of the shell in heat exchangerelationship with the cryogenic fluid internal tube, said warming fluidinternal tube connected between the warming fluid inlet port and thewarming fluid outlet port.
 20. The vaporizer of claim 19 wherein theshell is semi-circular and the cryogenic fluid and warming fluidinternal tubes feature circular helix geometries.